Nation One-fourth of US infrastructure is at risk of flooding amid ‘changing environment,’ report says October 11, 2021October 11, 2021 Doyle Rice and Celina Tebor, USA TODAY Comments Off on One-fourth of US infrastructure is at risk of flooding amid ‘changing environment,’ report says Flooding is the most expensive natural disaster in the US. A new report pinpoints who is most at risk: Louisiana, Florida, Kentucky and West Virginia.